Recently, a secondary battery which is rechargeable is being widely used as an energy source of a wireless mobile device. Also, a secondary battery is gaining attention as a power source of electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are suggested as an alternative of existing gasoline vehicles and diesel vehicles using fossil fuels involving an air pollution issue.
For a small mobile device, one or more (two or three) battery cells are used, and for a medium and large device such as a vehicle, a medium and large battery module implemented by electrically connecting a plurality of battery cells is used due to the need for high output and large capacity, and a battery pack implemented by connecting a plurality of battery modules may be also used.
As it is preferred to make a medium and large battery module as small and light as possible, a prismatic battery and a pouch-type battery that are stackable with high integration and have a low weight to capacity are mainly used as a battery cell applied in a medium and large battery module.
Particularly, a pouch-type battery cell using an aluminum laminate sheet as an exterior member is gaining much attention these days due to its advantages of light weight, a low manufacturing cost, and easy shape modification.
Also, for a medium and large battery module to provide an output and a capacity required for a certain apparatus or device, it is necessary to electrically connect a plurality of battery cells either in series or in parallel, or both and maintain a stable structure against an external force.
Referring to FIG. 1, in the case of a traditional battery module 1, structural stability is achieved by fixing and receiving a plurality of battery cells 2 using a module case 3 having a support structure for fixing the battery cells 2, and aside from this, connecting an electrode terminal 2a of the battery cell 2 to a sensing module 4 for sensing the voltage of each battery cell.
For the traditional battery module 1 to ensure dynamic stability, a module case having a complicated structure for fixing a battery cell stack structure is needed, and a separate process of electrically connecting the sensing module 4 to the battery cell 2 in a clip or welding manner is added, and thus, there are disadvantages of a complex process and an increased manufacturing cost.
That is, in the case of a wire type, assembly performance is excellent but a product cost increases due to addition of a wire component cost, and in the case of a welding type, a welding cost and efforts involved in welding is added and resistance against impact such as vibration is poor.
Therefore, to solve the problems, there is a need for a battery module having a structure that may be assembled through a simple process.